End cap locking mechanism for connecting pre-cast concrete structures

ABSTRACT

An end cap locking mechanism used to protect attachment means connecting pre-cast concrete structural members from exposure to adverse environmental conditions having an end cap and a connection sleeve, wherein the end cap is inserted into an end of the connection sleeve and engaged therein prohibiting any exposure of the attachment means to precipitation, which if exposed to such, could possibly corrode the attachment means. The position of the end cap is locked when inserted into the end of the connection sleeve by protrusion rings and cooperating recesses within both the end cap and the receiving section of the connection sleeve.

FIELD OF THE INVENTION

The present invention relates to an end cap that locks into an exposed end of a connection sleeve used in pre-cast concrete members. More particularly, the present invention relates to an end cap locking mechanism for covering an exposed end of a connection sleeve wherein the connection sleeve has disposed contains and protects an attachment means for connecting to pre-cast concrete structures. The end cap locking member of the present invention prevents the attachment means within a connection sleeve from being directly exposed to environmental conditions. If protection for the attachment means were to be neglected, metal of the attachment means would experience corrosion. Within a short period of time, the corrosion would weaken the strength and integrity of the attachment means thereby reducing the stability of the structure connected by the attachment means. More specifically, the present invention relates to an end cap locking mechanism for covering an exposed end of a connection sleeve. Located within the connection sleeve is an attachment means. An end cap is engages an opening at an end of the connecting sleeve and resiliently locks into the opening of the connection sleeve to provide a secure and tight fit. Additionally, the connection sleeve of the present invention can be formed in a particular shape and dimension so as to allow the attachment means to be adjusted within a range of motion.

BACKGROUND OF THE INVENTION

With the increasing number of construction projects, pre-cast concrete members are used frequently due to relative ease of installing the members by using cranes to position the members in place as opposed to conventional practices requiring the fabrication of forms and prolonged curing times. Typically, pre-cast concrete members are used to assemble highway overpasses, parking decks and various other projects, wherein horizontal and vertical members such as girders and columns are connected to one another.

Often the girders and columns have holes strategically positioned along through out to receive attachment means. When a girder and column are to be attached to one another, the holes are aligned and attachment means are inserted into both the holes in the girders and columns and tightened to produce a stable and secure structure. Long threaded bolts and large nuts and washers capable of bearing extremely heavy loads of weight are typical attachment means used to connect pre-cast concrete girders and columns.

Although, the attachment means are initially sufficient in strength to bare the intended weight of the structures, due to the exposure of adverse environmental conditions such as precipitation and wind, the integrity of the attachment means deteriorates as a result of corrosion. To resolve such problems earlier cover members were developed to shield the attachment means from exposure to such adverse conditions, thereby prolonging the life of the attachment means, and thus, the structure.

Although, earlier cover members were capable of shielding the attachment means from the adverse weather conditions, these cover members failed to provide a tight and secure fit for the cover, such that when positioned to cover the attachment means the cover would be resiliently locked in place. Thus, there is a need in the art to provide a cover member that tightly and securely attaches to a connection sleeve.

The earlier cover members also failed to provide protection for the attachment means from the weather and to provide a secure fit for covers which could accommodate attachment means that were bent or angled due to the misalignment of holes within the girders and columns. There also exists a need in the field to provide tight and secure fitting end caps within connection sleeves wherein the connection sleeves are capable of accommodating bent and slightly offset attachment means.

It is therefore, a primary object of the present invention to provide and end cap locking mechanism capable of providing the needed and desired durable permanently resiliently locking cover to protect and shield the attachment means within the pre-cast concrete structures.

It is a further object of the present invention to provide an end cap locking mechanism having a connecting sleeve and an end cap that together provide protection of the attachment means from adverse outside weather conditions. It is also an object of the present invention to accommodate attachment means which are bent or angled due to the misalignment of holes within the girders and columns, which otherwise would be incapable of proper attachment, or being protected.

Further objects and features of the present invention will become evident hereinafter.

SUMMARY OF THE INVENTION

The present invention is directed to an end cap locking mechanism used to cover threaded rods connecting pre-cast concrete structures by engaging an end cap into a connection sleeve to assume a locking position and also provide the threaded rod the capability of being adjusted about a range of motion within the connection sleeve of the end cap locking mechanism.

In the preferred embodiment, an end cap locking mechanism of the present invention is used to connect pre-cast concrete structures and comprises an end cap and a connection sleeve. The end cap has an outwardly extending protrusion ring disposed on and around the outside surface of the end cap. The connection sleeve has a first and second end, wherein the first end assumes an elongated tubular section disposed and the second end assumes a receiving unit. The receiving unit accepts and engages the end cap through use of a recess ring is disposed within and around the circumference of the receiving unit. The outwardly extending protrusion ring of the end cap directly engages the recess of the receiving unit in a resilient manner, thereby forcing the recess ring of the receiving unit outward, thereby locking the end cap within the receiving unit. The receiving unit has a width larger than the width of the elongated tubular section and upon insertion of the end cap into the receiving unit a surface of the end cap is flush with a surface of one of the pre-cast concrete structures.

Additionally, the end cap locking mechanism of the preferred embodiment of the present invention has a shoulder formed within the receiving unit to support a washer of an attachment means. During tightening of the attachment means, the washer abuts against the shoulder, thereby securing the connecting pre-cast concrete structures together. The present invention is not limited to a single protrusion ring and recess, but preferably an additional protrusion ring disposed on and around the circumference of the end cap and an additional recess disposed within and around the circumference of the receiving unit.

In another embodiment, an end cap locking mechanism of the present invention comprises an end cap and a connection sleeve. The connection sleeve has first and second ends wherein an expanded tubular section assumes the first end and a receiving unit assumes the second end. Positioned between the first and second ends of the connection sleeve is an elongated tubular section which is of a width smaller than widths of both the expanded tubular section and the receiving unit. Included within the receiving unit is a retaining cavity and containing unit, wherein the retaining cavity actively engages the end cap. The containing unit is enlarged to not only provide the required space for accepting a washer assembly, but is significantly larger in size than the size of the actual washer assembly. The additional enlarged size of the containing unit the washer assembly to move within the receiving unit to accommodate for the adjustments of an attachment member. Disposed on and around the circumference of the end cap is an outwardly extending protrusion ring that directly engages a recess disposed within and around the circumference of the holding member. The direct engagement of the outwardly extending protrusion ring of the end cap and the recess ring of the holding member forces the recess ring outwardly, which in turn, compels the holding member to resiliently contract. This relationship is what locks the end cap within the receiving member. Additionally, a shoulder is formed within the washer housing enabling the washer assembly to move against the shoulder to compensate for any angular displacement of the attachment means. The present invention is not limited to a single protrusion ring and recess, but preferably an additional protrusion ring disposed on and around the circumference of the end cap and an additional recess disposed within and around the circumference of the holding member.

In yet another embodiment, the end cap locking mechanism of the present invention comprises an end cap and a connection sleeve, wherein the end cap has a pair of inwardly tapering protrusions. Positioned between the pair of inwardly tapered protrusions is a v-shaped recess wherein a pair of inwardly tapering protrusions and the v-shaped recess are disposed on and around the circumference of the end cap. The connection sleeve has a first and second end wherein an expanded tubular section disposed at the first end and a receiving unit disposed at the second end of the connection sleeve. Assuming a position between the expanded tubular section and the receiving unit is an elongated tubular section which is of a width smaller than widths of the expanded tubular section and the receiving unit. Additionally, the end cap locking mechanism has an inwardly extending protrusion ring disposed within and around the circumference of the receiving unit, wherein the protrusion ring of the receiving unit directly engages the v-shaped recess of the end cap, thereby locking the end cap within the receiving unit. A shoulder is formed within the receiving unit to support a washer assembly of an attachment means, wherein the shoulder permits the washer assembly to slide about a range of motions in response to angular displacements of the attachment means. Furthermore, the receiving unit has a flat section that directly engages one of the inwardly tapering protrusions.

In each embodiment of the present invention, both the end cap and the connection sleeve are each made as unitary bodies and are preferably made from polyethylene and can be manufactured with a variety of dimensional cross-sections such as, but not limited to, rectangular, square, circular and polygonal shapes.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purposes of illustrating the invention, there is shown in the drawings, forms that are presently preferred; it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is an exploded and partially cut-away view of the connection sleeve for pre-cast concrete members showing the end cap locking mechanism of the present invention for receiving the end cap.

FIG. 2 is a partially cut-away view of the connection sleeve for pre-cast concrete members showing the end cap in locking position within the locking mechanism of the present invention and showing a threaded connection rod and bolt assembly in phantom within the sleeve.

FIG. 3 is a partially cut-away view of a second embodiment of the end cap locking mechanism for connecting pre-cast concrete members showing the end cap in locking position within the locking mechanism of the present invention and showing a threaded connection and bolt assembly in phantom within the sleeve with an expanded segment of the sleeve to accommodate a bent or angled rod.

FIG. 4 is a side view of a third embodiment of the connection sleeve for pre-cast concrete members with the end cap locking mechanism of the present invention having a rectangular end cap.

FIG. 5 is a side view of the third embodiment of the connection sleeve for pre-cast concrete members with the end cap locking mechanism of the present invention removed therefrom.

FIG. 6 is a top view of the connection sleeve showing the inner surfaces of the connection sleeve of the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed descriptions are for the best presently contemplated modes of carrying out the present invention. These descriptions are not intended in any limiting sense, but rather are made solely for the purposes of illustrating the general principles of the present invention.

Referring now to the drawings in detail, wherein like numerals indicate like elements, there is shown in FIGS. 1 and 2, an end cap locking mechanism 100 having a connection sleeve 125 and an end cap 150 embodying the principles of the present invention. Both the connection sleeve and the end cap can be made integrally through molding processes or separately through conventional plastic welding processes and, as such, each is formed separately as unitary bodies. The connection sleeve 125 is preferably of a tubular shape which has a hollow interior throughout the entire length of the connection sleeve 125. A bore axis 110 extends coaxially throughout the entire length of the hollow interior from a first end 125 a to a second end 125 b of the connection sleeve 125. A means for attaching two pre-cast concrete forms, such as a threaded rod, nut and washer assembly, is received and housed within the connection sleeve 125. The attachment means comprises, but is not limited to, a threaded rod 175, nut 177 and washer assembly 179, wherein the threaded rod has first and second ends 175 a and 175 b respectively as depicted in FIG. 2. Although a threaded rod, nut and washer assembly are the preferred means for attachment of the present invention, other means for attachment are conceivable. Both the connection sleeve 125 and the end cap 150 can be made from various polymers or plastics, but are preferably made from high density polyethylene material having color concentrate and an ultraviolet light inhibitor. The polyethylene material is desirable in that it is of sufficient strength, rigidity and has minimal flexibility, thereby providing a durable barrier for the attachment means as well as a secure fit when the end cap is engages the connection sleeve.

The present invention is to primarily be used on exterior or outside structures, whereby the entire end cap 150 and possibly part of the connection sleeve 125 will be subjected to environmental conditions, such as constant and direct exposure to ultraviolet light from the sun, as well all forms of precipitation and other weather conditions. The ultraviolet light inhibitor impregnated into the end cap 150 and connection sleeve 125 prevents discoloration and degradation of the end cap and the plastic prohibits any water from seeping through the end cap or connection sleeve. Additionally, the end cap locking mechanism also provides an aesthetically pleasing appearance, by covering the attachment means which, if not covered, would be an eyesore to individuals passing by.

The end cap locking mechanism 100 of the present invention is primarily made of two components, the connection sleeve 125 and the end cap 150, wherein each is made as a unitary body. A receiving unit 130 assumes a position on the first end 125 a of the connection sleeve 125 and receives, resiliently engages and holds the end cap 150 in a locking relationship with each other by way of protrusion rings and recesses which are described in more detail below.

Extending from the receiving unit 130 to the second end 125 b of the connection sleeve 125 is an elongated tubular section 140. As depicted in FIG. 2, a first interior bore 137 extends coaxially along the bore axis 110 throughout the entire length of the elongated tubular section 140. A second interior bore 139 also extends coaxially throughout the entire length of the receiving unit 130. Both first and second interior bores are coaxial with each other along the bore axis, but are of different diameters or widths. The diameter of the second interior bore 139 is significantly larger than that of the first interior bore 137. Forming the two bores with differing diameters creates a number of desirable features.

Firstly, at the transition point along the connection sleeve 125 where the first interior bore 137 is reduced to the second interior bore 139, a shoulder 132 is formed on a rear wall of the receiving unit 130. Due to relatively enlarged size of the shoulder, sufficient space is provided to accommodate the washer assembly 179. The shoulder 132 has both an interior and exterior surface 132 a and 132 b respectively, wherein the washer assembly 179 abuts against the interior surface 132 a of the shoulder and the exterior surface 132 b of the shoulder 132 abuts against the surface of the structure being connected (not illustrated), thereby sandwiching the shoulder 132 between the washer assembly 179 and the surface of the structure being connected. As such, when the attachment means is tightened, by rotation of the nut 177, the washer assembly 179 and the surface of the structure correspondingly squeeze the shoulder 132, providing a secure attachment, free of exposure to any environmental conditions. Secondly, the second interior bore 139 is of sufficient size not only to accommodate the size of the washer assembly 179 and the nut 177, but also to accommodate the insertion of a standard socket wrench to loosen or tighten the attachment means by engaging the nut 177.

The end cap 150 of the present invention is formed of a hollow unitary body having the bore axis 110 coaxially extending through first and second ends 151 and 153 respectively. Assuming the position at the first end 151 of the end cap 150 is a cover unit 151 a. When the end cap is inserted into the receiving unit 130 of the connection sleeve, the cover unit 151 a provides shielded protection for the attachment means by prohibiting any moisture from seeping into the second interior bore 139 of the connection sleeve 125. An apertured cavity 153 a assumes the location at the second end 153 of the end cap. Due to the apertured cavity 153 a having an opening, the second end 153 of the end cap 150 has a high degree of flexibility. It is desirable to have the second end 153 of the end cap 150 to be flexible, since when the end cap is inserted into the receiving unit 130 of the connection sleeve 125, the flexibility of the second end 153 of the end cap 150 provides an outward force against an interior surface 130 a of the receiving unit 130 which is critical to hold the end cap 150 within the receiving unit 130 of the connection sleeve 125. If the second end 153 were closed, the additional material covering the second end 153 of the end cap would create a rigid end cap, thereby restricting the flexibility of the second end 153 of the end cap 150. An additional desirable feature of the apertured cavity 153 a in the second end 153 of the end cap 150 is to provide additional space to accommodate for the first end 175 a of the threaded rod 175. If the second end 153 of the end cap 150 were covered, the end cap 150 would be unable to be fully inserted into the receiving unit 130 and as such, the first end 175 a of the threaded rod 175 would be need to be cut-off and removed to enable the end cap 150 to be fully and completely inserted into the receiving unit 130 of the connection sleeve 125.

Located on the exterior surface of the end cap 150 is a tapered protrusion ring 155 a which extending around the circumference of the exterior surface of the end cap 150. Extending away from the second end 153 of the end cap 150 and inwardly towards the bore axis 110, the tapered protrusion ring 155 a forms a cross sectional shape similar to that of a triangle. Also disposed on the exterior surface of the end cap is an arcuate protrusion ring 155 b, which extends around the circumference of the exterior surface of the end cap 150 and the apex of the arcuate protrusion ring 155 b extends outwardly and away from the bore axis 110 of the end cap 150. Both the tapered and arcuate protrusion rings, 155 a and 155 b, each have respective apices that extend away from and normal to the bore axis 110 at equal or substantially the same distances.

Regarding the receiving unit 130 of the connection sleeve 125, a reception aperture 134 exposing the bore axis 139 assumes a position at a first end 131 of the receiving unit 130 and the shoulder 132 as previously described, assumes a position at a second end 133 of the receiving unit 130, wherein the bore axis 110 extends from the first end 131 to the second end 133 of the receiving unit 130. Disposed on the interior surface 130 a of the receiving unit 130 is a tapered recess ring 135 a which extends around the circumference of the interior surface 130 a of the receiving unit 130. Strategically positioned at the end of the tapered recess ring 135 a of the receiving unit. 130 is an annular rim lock 136 a, which directly engages the end cap for the dual purpose of resiliently griping the end cap and restricting the end cap 130 from becoming dislodged from the receiving unit 130. Also located on the interior surface 130 a of the receiving unit 130 is an arcuate recess ring 135 b, which extends around the circumference of the interior surface 130 a. Both recess rings 135 a and 135 b each have ravines or troughs on the interior surface 130 a of the receiving unit 130, which are spaced from the bore axis 110 at distances equal to one another.

Prior to inserting the end cap 150 into the receiving unit 130 of the connection sleeve 125, the distances of the apices of the protrusion rings 155 a and 155 b and the ravines of the recess rings 135 a and 135 b are spaced away from the bore axis 110 at equal or substantially equal distances.

As illustrated in FIG. 2 of the present invention, after the attachment means 175 has been tightened and secured to hold the attached structures, the second end 153 of the end cap 150 is inserted into the receiving unit aperture 134. Upon insertion of the end cap 150 into the receiving unit aperture 134, the recess rings 135 a and 135 b located on the interior surface 130 a of the receiving unit 130, resiliently and respectively engage protrusion rings 155 a and 155 b of the end cap 150. The arcuate recess ring 135 b of the receiving unit 130 directly receives and engages the arcuate protrusion ring 155 b of the end cap 150. When the arcuate protrusion ring 155 b contacts the interior surface 130 a of the arcuate recess ring 135 b, the exterior surface of the arcuate protrusion ring 155 b pushes against the interior surface 130 a of the receiving unit 130, thereby forcibly displacing the arcuate recess ring 135 b outwardly and away from the bore axis 110. Likewise, when the tapered recess ring 135 a of the receiving unit 130 directly receives and engages the inwardly tapered protrusion ring 155 a of the end cap 150, the tapered recess ring 135 a is forcibly displaced outwardly and away from the bore axis 110. Due to directly engaging the protrusion rings 155 a and 155 b against the recess rings 135 a and 135 b, the inherent resiliency of the material used to make the receiving unit, conversely responds to the force exerted by the protrusion rings 155 a and 155 b, by providing an inward contraction force, which firmly and tightly holds the end cap 150 within the receiving unit 130.

Although the material used in the end cap locking mechanism of the present invention is resilient, the material also possesses an inherent rigidity as well. Due to the rigidity as well as the resilience of the material, the receiving unit conversely compels the walls to contract to re-establish a neutral state, thereby providing an extremely tight fit to not only prohibit wind gusts from disengaging the end cap, but also to seal out any precipitation, as well as preventing any careless removal of the end cap.

Since it is desirable to have the end cap fit tightly into the receiving unit, the end cap. 150 is forced into engagement with the receiving unit 130 either by hard strikes with an individual's hand or tools such as a rubber mallet or hammer. Due to the resilient and secure attachment of the end cap 150 to the receiving unit 130 of the connection sleeve, the end cap cannot be removed simply by an individual's hands. Should the need arise, wherein additional adjustment or removal of the attachment member 175 be required, appropriate tools need to be employed to separate the end cap 150 from the receiving unit 130. Although other ways are conceivable for removing the end cap from within the receiving unit, the end cap can preferably be removed without destroying the connection sleeve, by first drilling a hole in the end cap. Upon forming the hole, a rigid rod or hook can be inserted into the hole and used to pry or pull the end cap free from the receiving unit. After adjustments to the attachment member are made, a new end cap can be inserted back into the receiving unit to provide the needed protection from the elements and an aesthetically pleasing appearance.

Although not illustrated, the end cap locking mechanism of the present invention is typically used, but not limited to connecting pre-cast concrete sections wherein one of the surfaces of the sections will be exposed directly to external environmental conditions and/or directly displayed to the public. The surface of the structural concrete member exposed on the outside of the structure must have a hole extending through the structure with a similar cross-sectional profile to the connection sleeve 125 so as to enable the insertion of the connection sleeve into the hole. The shoulder 132 of the receiving unit 130 should abut against the corresponding cross-sectional profile in the pre-cast concrete structural member at such a position such that when the end cap 150 is inserted into the receiving unit 130 of the connection sleeve 125, the cover unit 151 a of the end cap 150 will be flush with the exposed surface of the structure. Additionally, after insertion of the end cap into the receiving unit, any visible appearance of the hole in the pre-cast concrete structural member should have substantially disappeared.

As illustrated in FIG. 3, the second embodiment of the present invention depicts an end cap locking mechanism 200 having a connection sleeve 225 for receiving and containing an attachment member 275. Positioned at a first end 225 a one end of the connection sleeve is a receiving unit 230, which resiliently receives and holds an end cap 250. Located at a second end 225 b of the connection sleeve 225 is a tubular expanded unit 242 for housing and holding the threaded rod 275. Assuming the position at a first end 275 a of the threaded rod 275 are a nut and washer assemblies 277 and 279 respectively. The second end 275 b of the threaded rod can permanently or adjustably affixed to an existing structure. The tubular expanded unit 242 provides the extra space required to enable the threaded rod 275 to radially move within a limited range of motion about a bore axis 210 of the connection sleeve 225. Due to the enlarged size of the tubular expanded unit 242, the connection sleeve of the present invention can be used with threaded rods that are bent and/or rods inserted through holes of the connecting structure that are in misalignment. As depicted in FIG. 3, the threaded rod is radially displaced from the bore axis 210, wherein the second end 275 b of the threaded rod 275 is slightly displaced and amply accommodated by the enlarged size of the tubular expanded unit 242.

The end cap 250 is formed of a hollow unitary body having a bore axis 210 coaxially extending through first and second ends 251 and 253 of the end cap, respectively. Assuming the position at the first end 251 of the end cap 250 is a cover unit 251 a. When the end cap is inserted into the receiving unit 230 of the connection sleeve 225, the cover unit 251 a provides shielded protection for the attachment means by prohibiting any moisture from seeping into the receiving unit 230 of the connection sleeve 225. An apertured cavity 253 a assumes the location at the second end 253 of the end cap 250. Due to the apertured cavity 253 a having an opening, the second end 253 of the end cap 250 has a high degree of flexibility. It is desirable to have the second end 253 of the end cap 250 to be flexible, since when the end cap 250 is inserted into the receiving unit 230 of the connection sleeve 225, the flexibility of the second end 253 of the end cap 250 provides an outward force against an interior surface 230 a of the receiving unit 230 which is critical to hold the end cap 250 within the receiving unit 230 of the connection sleeve 225. If the second end 253 of the end cap 250 were closed off, the additional material covering the second end 253 of the end cap 250 would rigid, thereby undesirably restricting the flexibility of the second end 253 of the end cap 250. An additional desirable feature of the apertured cavity 253 a in the second end 253 of the end cap 250 is to provide additional accommodating space for the first end 275 a of the threaded rod 275. If the second end 253 of the end cap 250 were covered, the first end 275 a of the threaded rod 275 would be need to be cut off to enable the end cap 250 to be fully and completely inserted into the receiving unit 230 of the connection sleeve 225.

Located on an exterior surface of the end cap 250 is a tapered protrusion ring 255 a which extends around the circumference of the exterior surface of the end cap 250. Extending away from the first end 251 of the end cap 250 and inwardly extending towards the bore axis 210 and in the direction of the second end 253 of the end cap 250, the tapered protrusion ring 255 a forms a cross sectional shape similar to that of a triangle. Also disposed on the exterior surface of the end cap is an arcuate protrusion ring 255 b, which extends around the circumference of the exterior surface of the end cap 250. Both the tapered and arcuate protrusion rings, 255 a and 255 b, each have respective apices that extend away from and normal to the bore axis 210 at equal or substantially the same distances.

Regarding the receiving unit 230 of the connection sleeve 225, a reception aperture 234 assumes a position at a first end 231 of the receiving unit 230 and the shoulder 232 as previously described, assumes a position at a second end 233 of the receiving unit 230, wherein the bore axis 210 coaxially extends from the first end 231 to the second end 233 of the receiving unit 230. Disposed on an interior surface 230 a of the receiving unit 230 is a tapered recess ring 235 a which extends around the circumference of the interior surface 230 a of the receiving unit 230. Strategically positioned at the end of the tapered recess ring 235 a of the receiving unit 230 is an annular rim lock 236 a, which directly engages the end cap cover unit 251 a for the dual purpose of resiliently griping the end cap and restricting the end cap 230 from becoming outwardly dislodged from the receiving unit 230 in a direction parallel to the bore axis 210. Also located on the interior surface 230 a of the receiving unit 230 is an arcuate recess ring 235 b, which extends around the circumference of the interior surface 230 a. Both recess rings 235 a and 235 b each have ravines on the interior surface 230 a of the receiving unit 230, which are spaced away and normal to the bore axis 210 at equal distances.

The recess and protrusion rings, 235 a, 235 b, 255 a and 255 b of the second embodiment of the present invention, respectively engage each other in the same relationship as described above with respect to the first embodiment of the present invention.

The receiving unit 230 of the second embodiment of the present invention is different than that of the first embodiment in that receiving unit 230 comprises a retaining cavity 237 and a containing unit 238, wherein the containing unit 238 is larger in diameter or width about the bore axis 210 than that of the retaining cavity 237. The containing unit 238 of the second embodiment of the present invention is also larger in size to that of the receiving unit 130 of the first embodiment. Due to the expanded size of the containing unit, additional area or space is created to enable the washer assembly 279 to move about an extended range of motion along a shoulder 232, wherein the washer traverses its range of motion in a direction perpendicular to that of the bore axis 210. This range of motion enables the use of the present invention in the case where the holes within the connecting pre-cast concrete members are not in alignment or the threaded rod is bent. As illustrated in FIG. 3, due to the misalignment of the holes within the pre-cast concrete structural members (not illustrated), the second end 175 b of the threaded rod 275 is offset from the bore axis 210 at a slight angle, thereby requiring the washer assembly 279 to move normal to the bore axis 210 along the shoulder 232 to accommodate for the corresponding movement of the first end 275 a of threaded rod 275 a. The increased diameter or width of the containing unit 238 provides a sufficient range of motion so as to permit the threaded rod 275 to radially fluctuate along the order of ±5 degrees with respect to the bore axis 210 of the connection sleeve 225.

The connection sleeve of the second embodiment of the present invention is different than that of the first embodiment in that tubular expanded unit 242 is of greater diameter or width about the bore axis than elongated tubular section 140 of the first embodiment. When used in conjunction with the containing unit 237, the tubular expanded unit 242 provides the necessary enlarged size to accommodate for the radial displacement of the threaded rod 275. As such, when the threaded rod is radially displaced from the bore axis 210, the washer assembly 279 is also displaced radially from the bore axis 210. Assuming the position between the tubular expanded unit 242 and the receiving unit 230, is an elongated tubular unit 240. Located along the tubular expanded unit 242 is a flange unit 244 and an extension unit 246. The flange unit 244 has an interior bore which gradually expands in a direction away from the first end 225 a of the connection sleeve and toward the second end 225 b of the connection sleeve 225 to provide the needed size to accommodate the required range of motion of the second end 275 b of the threaded rod 275. Although the connection sleeve of the present invention preferably offers a radial range of motion of approximately ±5 degrees with respect to the bore axis 210 of the connection sleeve 225, the range of motion is not limited to such, since by simple adjustments of increasing the diameter or widths of the washer housing 238 and the tubular expanded section 242, accommodation for substantially higher degrees of movement is easily attainable.

As illustrated in FIGS. 4-6, the third embodiment of the present invention depicts an end cap locking mechanism 300 having a connection sleeve 325 and an end cap 350. Both the connection sleeve and the end cap are formed separately as unitary bodies. Assuming a position at a first end 325 a of the connection sleeve 325 is a receiving unit 330 similar to the first and second embodiments of the present invention in that a shoulder 332 is disposed on a rear wall thereof, but different in that the receiving unit of the third embodiment does not have any recesses therein to resiliently hold the end cap 350, but instead uses an inwardly extending protrusion annulus 335 to hold the end cap 350 within the receiving unit 330. Assuming a position at a second end 325 b of the connection sleeve 325 is a tubular expanded unit 342 and disposed between the receiving unit 330 and a tubular expanded unit 342, is an elongated tubular unit 340. Similar to that of the second embodiment of the present invention, shoulder 332 of third embodiment of the present invention is of sufficient size so as to accommodate for radial movements of the washer assembly caused by the radial movements of the threaded rod.

The receiving unit 330 of the connection sleeve 325 of the present invention frictionally and resiliently engages the end cap 350. Located on an exterior surface of the end cap 350 5 and positioned around the circumference of the end cap are first and second tapered protrusions rings 357 and 359, respectively. Assuming a position at a first end 351 of the end cap 350 is a cover unit 351 a and located at a second end 353 of the end cap 350 is an apertured cavity 353 a. As illustrated in FIG. 4, the first tapered protrusion ring 357 assumes a cross-sectional profile including a planar member 357 a and a tapering member 357 b, which gradually tapers inwardly towards the bore axis 310 and in a direction away from the first end 351 of the end cap 350 and towards the second end 353 of the end cap 350. The second tapered protrusion ring 359 has a cross-sectional profile, wherein an arcuate extension 359 a protrudes in a direction normal to the bore axis 310 and a sloping member 359 b, which gradually tapers inwardly towards the bore axis 310 and in a direction away from the first end 351 of the end cap 350 and towards the second end 353 of the end cap. At the transition point along the end cap where the first tapered protrusion ring 357 becomes the second tapered protrusion ring 359, a v-shaped recess ring 358 is formed. Extending outwardly and away from the v-shaped recess ring 358 is the arcuate extension 359 a having an apex adjacent to the v-shaped recess ring 358. As such, both the tapering member 357 b and the sloping member 359 b of the end cap 350 inwardly extend toward the bore axis 310 of the end cap 350.

The receiving unit 330 of the present invention is formed of a particular contour and shape so as to securely retain the end cap 350 once fully inserted within the receiving unit 330 of the connection sleeve 325. Assuming a position at a first end 331 of the receiving unit 330 is a flat reception unit 339 and the inwardly extending arcuate protrusion annulus 335, wherein the arcuate protrusion annulus 335 is composed of first and second arcuate units 335 a and 335 b respectively. The second arcuate unit 335 b is of a steeper slope or contour than the first arcuate unit 335 a. Assuming a position at a second end 333 of the receiving unit 330 is shoulder 332 wherein the washer assembly as discussed in previous embodiments, abuts against to provide support for the structures being attached. Once the end cap 350 is fully and completely inserted into the receiving unit 330 of the connection sleeve 325, the flat reception unit 339 actively engages the planar member 357 a of the first tapered protrusion ring 357 and the arcuate protrusion annulus 335 directly engages the v-shaped recess ring 358. More particularly, the second arcuate unit 335 b of the arcuate protrusion annulus 335 abuts against the arcuate extension 359 a of the second tapered protrusion ring 359 and securely held within the connection sleeve, due in part to the steep contour of the second arcuate unit 335 b, which restricts the end cap from being dislodged outwardly from the receiving unit in a direction parallel to the bore axis. Strategically positioned on the end of the flat reception unit 339 of the receiving unit 330 is an annular rim lock 336 a, which directly engages the cover unit 351 a of the end cap 350 for the dual purpose of resiliently griping and holding the end cap as well as securely retaining the end cap 350 within the receiving unit 330.

Similar to the other embodiments of the present invention, prior to inserting the end cap into the receiving unit, the exterior surface of the v-shaped recess 358 is the same diameter or width as the apex of the interior surface of the inwardly extending arcuate protrusion annulus 335 of the receiving unit 330. Likewise, the interior surface of the flat reception unit 339 is also the same diameter or width about the bore axis 310 as the exterior surface of the planar member 357 a of the first tapered protrusion 357. Whereupon insertion of the end cap into the receiving unit, the apex of the inwardly extending arcuate protrusion annulus 335 actively engages the v-shaped recess ring 358 of the end cap 350 and the planar member 357 a actively engages the flat reception unit 339 of the receiving unit 330, thereby outwardly forcing the flat reception unit 339 and the arcuate protrusion annulus 335 away from the bore axis 310 to compel the receiving unit 330 to respond with a contraction force directed inwardly towards the bore axis 310 to securely hold and retain the end cap 350 within the receiving unit 330 of the connection sleeve 325.

FIG. 6 illustrates a cross-sectional end view of the connection sleeve 325 of the third embodiment of the present invention depicting the inner surfaces as taken along line 6-6 of FIG. 5. As shown through this illustration, a first interior bore 337 of the elongated tubular unit 340 can be seen, which extends from the shoulder 332 of the receiving unit to the tubular expanded unit 342. A second interior bore 341 coaxial with the first interior bore 337 and corresponding to the bore within the tubular expanded unit 342 of the present invention can also be viewed and has a diameter significantly larger than that of the first interior bore 337 to accommodate for the radial movements of a threaded rod disposed therein. A portion of the receiving unit 330 of the present invention is also illustrated, wherein the flat reception unit 339 and the annular rim lock 336 a are disposed on and around the circumference of the receiving unit 330, which in turn receives, engages and retains the end cap within the receiving unit 330 of the connection sleeve, thereby establishing a tight and secure end cap locking mechanism of the present invention.

Due to the versatility of the present invention to be used for a variety of the applications, the connection sleeve of the present invention can be constructed in varying lengths and diameters. Preferably, the connection sleeve of the present invention is typically applicable to both small and large applications. For instance, small applications wherein the present invention is used to add fascia to existing exterior walls or uniting step systems to walls, wherein a connection sleeve having a length of approximately 15 inches, when measured along the bore axis, would be of sufficient length to house and protect the attachment means therein. For larger applications, such as connecting structural pre-cast concrete members to columns in a building or other similar applications dealing with substantial weight, connection sleeves typically having a length of around 30 inches, when measure along the bore axis, are used to house and protect the attachment means needed to connect structures of such size. For smaller applications, connection sleeves typically have receiving units and expanded tubular sections along the order of 1 to 3 inches about the bore axis and elongated tubular sections ranging from ½ to 1½ inches. As for larger applications utilizing large attachment means, connection sleeves typically have receiving units and expanded tubular sections along the order of 3 to 6½ inches about the bore axis and elongated tubular sections ranging from 2 to 3 inches. Although, the receiving unit 330 and the end cap 350 of the present invention in FIG. 6 appears square shaped, other shapes can be used for the end cap and the receiving unit, such as circular, rectangular or polygonal.

It should now be appreciated that the practice of the present invention provides an end cap locking mechanism for attachment means disposed in pre-cast concrete structural members wherein the end cap locking mechanism provides an exceptionally tight and secure fit for retaining an end cap within a connection sleeve and the connection sleeve is constructed in such a manner so as to accommodate for bent or angled attachment means.

Although the description has been primarily related to pre-cast concrete structural members, the principles of the end cap locking mechanism of the present invention are equally applicable to other materially different types of structures. For instance, the practice of the present invention may very well find application by providing coverage for attachment means connecting wooden and metal structural members. Thus, these other materials are also contemplated to be used with the present invention, and the respective end caps should be of similar color or design to the structure being connected.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, the described embodiments are to be considered in all respects as being illustrative and not restrictive, with the scope of the invention as well as all modifications which may fall within a range of equivalency which are also intended to be embraced therein. 

1. An end cap locking mechanism for connecting pre-cast concrete structures comprising an end cap and a connection sleeve, the connection sleeve has an expanded tubular section disposed at one end, a receiving unit disposed at the other end, and an elongated tubular section disposed therebetween, and being of a width smaller than the widths of both the expanded tubular section and the receiving unit, the receiving unit has a holding member and a washer housing, wherein the holding member receives and holds the end cap and the washer housing provides the needed space for a washer to move therein to accommodate for the adjustments of an attachment member, said washer housing has a larger width than that of the holding member, disposed on and around the circumference of the end cap is a protrusion ring that directly engages a recess disposed within and around the circumference of the holding member, thereby locking the end cap within the receiving member.
 2. The end cap locking mechanism of claim 1, wherein the end cap and the connection sleeve are unitary bodies.
 3. The end cap locking mechanism of claim 1, wherein the end cap and the connection sleeve are made from polyethylene.
 4. The end cap locking mechanism of claim 1, wherein a shoulder is formed within the washer housing enabling the washer to adjustably abut thereagainst.
 5. The end cap locking mechanism of claim 1, wherein an additional protrusion ring is disposed on and around the circumference of the end cap and an additional recess is disposed within and around the circumference of the holding member.
 6. An end cap locking mechanism for connecting pre-cast concrete structures comprising an end cap and a connection sleeve, the end cap having a pair of inwardly tapering protrusions and a v-shaped recess disposed therebetween, wherein the pair of inwardly tapering protrusions and the v-shaped recess is disposed on and around the circumference thereof, the connection sleeve has an expanded tubular section disposed at one end, a receiving unit disposed at the other end, and an elongated tubular section disposed therebetween, and being of a width smaller than widths of the expanded tubular section and the receiving unit, an inwardly extending protrusion ring is disposed within and around the circumference of the receiving unit, wherein the protrusion ring of the receiving unit engages the v-shaped recess of the end cap, thereby locking the end cap within the receiving unit.
 7. The end cap locking mechanism of claim 6, wherein the end cap and the connection sleeve are each made as unitary bodies.
 8. The end cap locking mechanism of claim 6, wherein the end cap and the connection sleeve are made from polyethylene.
 9. The end cap locking mechanism of claim 6, wherein a shoulder is formed within the receiving unit to support a washer of an attachment means.
 10. The end cap locking mechanism of claim 6, wherein the receiving unit has a flat section which directly engages one of the inwardly tapering protrusions. 